38 | New Scientist | 13 February 2021half are in poor shape, battered by unregulated,
unreported and illegal fishing.
Hang on, you might think, what about the
FAO’s assessment that two-thirds of stocks
are sustainable? There is no contradiction,
says Barange. FAO and Aichi use different
definitions of “stock”. FAO thinks in terms of
vast commercial stocks; Aichi in terms of
smaller ones defined by ecology. “It depends
what units you use,” says Barange.
Another major concern is that sustainable
doesn’t necessarily mean environmentally
benign. Large-scale commercial fishing, which
began in earnest around 1950, can have many
negative impacts on the wider ecosystem, such
as the accidental catch of non-target species,
called by-catch. Most of the fish, seabirds and
other unfortunate creatures that are caught by
accident are dead or dying by the time they are
tossed back into the sea. By-catch has fallen
dramatically, from about 40 per cent of the
overall catch in 2000 to about 10 per cent in
2014, but it is still considered “unsustainable”
by the Convention on Biological Diversity. A
recent study by WWF concludes that it kills
more than a million marine mammals,
reptiles and birds every year.
Lost or discarded fishing equipment is also
a problem. According to some estimates,
between 640,000 and 800,000 tonnes of
“ghost gear” is cut adrift each year, killing
untold numbers of marine animals that get
caught up in it.
Certain fishing methods can also take a toll.
Bottom trawling, where nets are dragged along
the seabed, indiscriminately disrupts and
damages marine habitats, possibly even
contributing to pollution by undermining
the ability of sea-floor microbes to remove
harmful sediments.
According to the International Union for
Conservation of Nature, which keeps track of
the impacts of fisheries on threatened species,
fisheries have a net negative impact, and the
extinction pressure they create is growing.
Even the concept of sustainability has been
questioned. “The word ‘sustainable’ doesn’t
mean anything,” says Daniel Pauly at the
University of British Columbia in Vancouver.
“You can actually overfish sustainably – you
can reduce the stock to a tiny fraction of
its original abundance and fish the rest
sustainably. It’s like cutting an immense
forest, but leaving a few trees standing, which
you harvest sustainably.” The Canadian cod
fishery once yielded 200,000 tonnes a year, forBiodiversity Targets (2010) and then the
Sustainable Development Goals (2015), which
both pledged to end overfishing of wild stocks
by 2020 and were adopted by the more than
190 member nations of the UN.
According to Barange, the Code of
Conduct was a partial success. It slowed the
rate at which stocks were slipping into the
“overfished” column. From 1974 to 1995,
20 per cent of stocks flipped from sustainable
to unsustainable. In the 25 years since, only
another 5 per cent have become unsustainable.
“We are flattening the curve,” says Barange.
“But not sufficiently.”
The Sustainable Development Goals,
however, have had no discernible impact. They
are framed explicitly in terms of managing fish
stocks: to end overfishing by 2020 and rebuild
by 2030. The 2020 target was missed, and the
2030 one is out of reach. Recovery of an
overfished stock takes two to three times the
species’ life span; an Atlantic cod, which is oneof the most overfished species, can live for
25 years, for example. “We are making progress,
but it is geographically uneven and not fast
enough,” says Barange.
As for the Aichi targets, forget it. The 20 goals
were supposed to be met by the end of last
year, but, to a first approximation, have been
completely missed. The specific target for
fish set out four aims: end overfishing, put
recovery plans in place, eliminate significant
negative impacts on threatened species and
vulnerable ecosystems, and remain within
safe ecological limits. None were met. Some
progress has been made on overfishing and
recovery plans, but on the other two there has
been “no significant change” since the targets
were set in 2010.Conflicting definitions
Even where progress has been made, it is
insufficient. Where fish stocks are carefully
monitored and assessed and managed with
an understanding of how species fit within a
broader ecosystem, overfishing has stopped
and recovery is under way. But only half of the
world’s stocks are managed like this. The otherFrom top: Aquaculture off the
coast of Majorca, Spain; oyster
farm in Arcachon Bay, FrancePH
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